Certain heat pump systems include a sealed system for chilling and/or heating air with refrigerant. The sealed systems generally include a throttling device for restricting a flow of refrigerant between an outdoor heat exchanger or coil and an indoor heat exchanger or coil of the sealed system. Various throttling devices are available, including capillary tubes, J-T valves, electronic expansion valves, etc. Within the throttling device, at least a portion of the refrigerant within the flow of refrigerant may vaporize.
Packaged terminal air conditioner units generally include a casing and a sealed system. Due to space constraints within the casing, selection of sealed system components for packaged terminal air conditioner units can be limited. For example, relatively small heat exchangers are generally used in packaged terminal air conditioner units due to space constraints within the casing. Utilizing small heat exchangers can result in a large pressure drop across the low pressure side heat exchanger and thereby negatively affect an efficiency of the packaged terminal air conditioner unit. To reduce such pressure drops, certain small heat exchangers include large diameter tubes and/or split refrigerant flow into multiple parallel tubes. However, such small heat exchangers reduce refrigerant velocity through the small heat exchangers and the refrigerant side heat transfer coefficient.
Accordingly, a device for reducing a pressure drop of refrigerant across a heat exchanger of the packaged terminal air conditioner unit would be useful. In particular, a device for reducing a pressure drop of refrigerant across a heat exchanger of a packaged terminal air conditioner unit without significantly reducing the refrigerant side heat transfer coefficient would be useful.